Esboço de gráficos: rigor na abordagem de funções quadráticas

Abstract

The present work aims to develop a teaching proposal in mathematics for high school students. The content addressed in the proposal are graphs of functions, especially the graph of the quadratic function: the parabola. The need for greater mathematical rigor in explaining the justification of the quadratic function graph to be a parable has led us to develop a lesson plan proposal with more rigorous mathematical explanations and definitions than are currently presented in textbooks. We used algebraic calculations for the demonstrations and also made use of a practical material, a white board where we have attached a square, and with the use of pins, string and whiteboard brush we can draw the parable taking into account its property. The practical material helps in the explanation as well as visually exemplifies what we want to show with the algebraic calculations. The proposal was presented to the students of two schools, one state public and the other private, which I teach in the city of Viçosa - MG and was also presented to six mathematics teachers, co-workers, five of these teachers from state, municipal and state public schools. private schools of the municipality of Viçosa - MG and a teacher of a state public school in the municipality of Teixeiras - MG.